The present invention relates to a mechanical device having a sealing means and a method of mounting the sealing means to the mechanical device.
Different types of sealing means for mechanical devices are known. Special sealing means are required when sealing a rotating shaft from its housing, i.e, from the non-rotating surrounding parts of the mechanical device. In GB-A-2 137 702, an oil sealing means is shown which, on the one hand, is arranged to seal against the surface of a rotating shaft and, on the other hand, is arranged to seal against the non-rotating housing. A cylindrical elastomeric sleeve is adapted to be received over the outside diameter of the shaft, to seal against the shaft. A further traditional sealing means seals against the housing. The sleeve has to be pressed on the shaft, because of the tight fit required between the sleeve and the shaft. The sealing material of the sleeve is therefore easily cut or otherwise damaged during this operation, especially if the shaft is provided with sharp cornered splines, of the same diameter as the shaft, at the outgoing end of the shaft.
The object of the present invention is to provide a mechanical device, which has an easy-to-mount sealing means.
A further object of the invention is to provide a mechanical device, which has a more effective sealing means.
These objects are achieved with a mechanical device which includes a shaft, a sealing device for sealing around the shaft, a housing, and a first abutment means; where the sealing device comprises carrier means on which a plurality of sealing elements are arranged. The mechanical device further includes an enclosure means, and the sealing device further comprises a first sealing element having an inner dimension which is larger than the outer dimension of the shaft. The enclosure means at least partially encloses the first sealing element, so that after the sealing means has been mounted and compressingly fastened in the mechanical device, the first sealing element is compressed in a first direction (A) axially along the shaft and expanded in a second direction (B) radially towards the shaft, so that a first contact surface of the first sealing element is in contact with the first abutment means and a second contact surface of the first sealing element is in sealing engagement with the shaft.
A further object of the invention is to provide a method of mounting the sealing means according to the invention to a mechanical device.
This object is achieved with a method of mounting the sealing means to the mechanical device including:
i) arranging the first abutment means on the shaft;
ii) arranging the first sealing element, and the first carrier means and the second carrier means, over the shaft;
iii) arranging the second abutment means onto the shaft;
iv) fastening the sealing means in the mechanical device, by compressing the second abutment means towards the first abutment means, thus compressing the first sealing element in the first direction (A), axially along the shaft, and expanding the first sealing element in the second direction (B), radially towards the shaft, thus bringing a first contact surface of the first sealing element in contact with the first abutment means and a second contact surface of the first sealing element in sealing engagement with the shaft; and
v) fastening the second abutment means on the shaft.
This object is also achieved with a method of mounting the sealing means to the mechanical device by:
i) arranging the first abutment means onto the shaft;
ii) arranging the first carrier part onto the shaft;
iii) arranging the second carrier part on the first carrier part;
iv) arranging the second abutment means onto the shaft;
v) fastening the sealing means in the mechanical device by compressing the second abutment means towards the first abutment means, thus compressing the first sealing element in the first direction (A), axially along the shaft and expanding the first sealing element in the second direction (B), radially towards the shaft, thus bringing a first contact surface of the first sealing element in contact with the first abutment means and a second contact surface of the first sealing element in sealing engagement with the shaft; and
vi) fastening the second abutment means on the shaft.
Further preferred embodiments are disclosed in the appended dependent claims.